It would appear the cloud of Icelandic Volcano Ash – spouting from beneath the Eyjafjallajökull glacier - has now grounded aircraft in most of Northern Europe. (Ash cloud image via eumetsat.int).
As I write this, I’m looking at my Plane Finder iPhone app (free version), and the FlightRadar24.com website. The skies are empty across the UK, Scandinavia, Germany and Northern France. The only plane this side of Poland heading north is an Emirates Sky Cargo 747.
Volcanic Ash – particularly where the ejected material is quickly cooled by water vapour - is a mixture of rock particles and tiny bits of glass, which is almost the perfect combination of materials to knacker a jet engine. The rock abrades sensitive components and blocks air filters, while the glass melts into a sticky, boiling hot soup that block sensors and solidifies as it leaves the hottest part of the engine. The effect can be catastrophic.
An incident I recall reading about was the story of British Airways Flight 9, a Boeing 747 caught in an ash cloud ejected by Mount Galunggung in 2009. Captain Eric Moody’s announcement was the sort of understatement that makes one proud to be British:
Ladies and gentlemen, this is your captain speaking. We have a small problem. All four engines have stopped. We are doing our damnedest to get them under control. I trust you are not in too much distress.
After some frantic procedures, reading the manual and pondering the thought of becoming the first crew to ditch a 747 in the ocean, the two pilots and flight engineer managed to restart the engines and limp to the nearest runway through ash-clouded skies with a windscreen ash-abraded to the point of being opaque. Captain Moody later described it as:
a bit like negotiating one's way up a badger's arse
If you’re a holiday maker, try not to be too upset about your cancelled flights; better an unexpected coach trip than a memorial service. And consider that Flight 09 encountered a dust cloud with relatively little glass content.
